`sig
type t = Mutex.t
val create : unit -> Core_mutex.t
val equal : Core_mutex.t -> Core_mutex.t -> bool
val lock : Core_mutex.t -> unit
val try_lock : Core_mutex.t -> [ `Acquired | `Already_held_by_me_or_other ]
val timedlock : (Core_mutex.t -> Time.t -> bool) Core_kernel.Std.Or_error.t
val unlock : Core_mutex.t -> unit
val critical_section : Core_mutex.t -> f:(unit -> 'a) -> 'a
val synchronize : ('a -> 'b) -> 'a -> 'b
val update_signal : Core_mutex.t -> Condition.t -> f:(unit -> 'a) -> 'a
val update_broadcast : Core_mutex.t -> Condition.t -> f:(unit -> 'a) -> 'a
end`